Ad-hoc inter-vehicle networks will soon be a reality as cars become equipped with wireless communication system.
One use of an inter-vehicle network is
to propagate alerts such as accidents and road conditions
within a region.
Unlike previous work in the
area that focuses on instantaneous delivery of an alert
to all reachable cars, this work studies the problem
where an alert needs to be maintained for a duration
of time.
In this paper, we formally define the problem
and its correctness.
We provide an efficient protocol
that minimizes the number of broadcasts needed for
maintaining a regional alert over a period of time, and
we evaluate our protocol through simulation.